Patent GB-432813-A (GB)
Title: Apparatus for use in the stringing of tennis and like racquets
IPC: A63B51/14
Filed: 1934-02-19
Abstract: 432,813. Racket - stringing devices. SIEFF, S. H., 30, Mildmay Park, and PRITCHARD, A., 40, Peartree Street, Goswell Road, both in London. Feb. 19, 1934, No. 5461. [Class 132 (ii)] A shedding device for separating the main strings to facilitate transverse stringing also provides a channel or guideway for positively guiding a cross-string between the main strings. Each shedding device comprises a plurality of oscillatable elements 1 pivoted on extensions 2 of a frame 3, and biassed, for example, by coil springs normally to assume the vertical position. The elements 1 are rocked in either direction to the horizontal position Fig. 2, by cam elements 7 on a bar 8 slidable in frame 3, when the grooves 5 in the elements engage and separate alternate main strings 52 and grooves 6 in the elements 1 line up to form a guide channel through which the transverse string is threaded. The bar 8 is reciprocated through a floating rack 12 by rocking an arm 11 rigid with a pinion 13 meshing with the rack, and is enclosed by a fixed cover plate 17, and by a vertically sliding cover plate 19 notched at 20, which, in the lower position serves to enclose the guide channel. In operation, the lever 11 is rocked to the normal position (full) shown in Figs. 2, 3, to rock the elements 1 to form the guide channel, and a pin 23 on pinion 13 engaging in a slot 22 in the movable cover 19, depresses it to enclose completely the guide channel. The lever 11 is locked against further depression by a spring plunger 30, mounted on the movable cover 19, engaging in a slot 31 in the sliding bar 8, Fig. 2. After the crossstring is threaded, a lever 25 pivoted at 25<a> to the cover 17 is depressed. A pin 24 thereon elevates the movable cover 19 and with it the plunger 30 from the slot 31 whereupon the arm 11 is rocked beyond normal to the dotted position, Fig. 2 where the elements 1 are released and return to the vertical. The shedding device is now moved to the next cross-stringing position when the lever 11 is rocked in the opposite direction to the other normal position, the elements 1 being thereby rocked in the reverse direction to form the shed. After stringing, lever 25 is depressed to permit further rotation of lever 11 as before to release the strings, when the shedding device is moved to the next stringing position and the operations repeated. The frame 3 is detachably mounted on a carriage 34 to facilitate positioning of the racket frame 51, the carriage being slidable on a guide rail 32 mounted on a base plate 33. Two shedding devices as shown are preferably used for working simultaneously from the two central cross-strings outwardly as described in Specification 388,793, the frames 34 of each being moved together, from one stringing position to the next, by a turnkey 43 acting through bevel gears 42, pinion 41, and racks 40 rigid with frames 34, which are held in each stringing position by spring catches 44 engaging teeth 45 in the base plate. The strings at the narrow ends of the racket are preferably strung by hand but the shedding devices may be reduced in width by removing parts 1 thereof to enable them to be used at these positions.